Pool covers

Abstract

A device for covering a pool, for example a swimming pool, has an upper component composed of a closed cell polymeric foam and a lower component composed of an open cell polymeric foam. The device can have, or can acquire in use, a convex upper surface which reduces the danger that it will be blown off the pool by wind.

The invention claimed is: 
     
       1. A method of covering an exposed surface of water in a swimming pool, the method comprising maintaining a plurality of generally laminar covering members on the surface, each of the covering members comprising
 (1) an upper component which is composed of a closed cell polymeric foam and which has an upper surface, at least part of the upper surface being convex, and the upper surface being (i) above the surface of the water and (ii) substantially impermeable to water, and 
 (2) a lower component which (i) is secured to the upper component, and (ii) comprises a lower portion which is immersed in the water and comprises an open cell polymeric foam having water absorbed therein. 
 
     
     
       2. A method according to  claim 1  wherein each of the covering members consists essentially of the upper component and the lower component. 
     
     
       3. A method according to  claim 2  wherein the upper component has a thickness of 7-60 mm and the lower component has a thickness of 0.5-40 mm. 
     
     
       4. A method according to  claim 3  wherein each of the covering members is a monolithic article wherein the upper component has a thickness of 20-40 mm, and the lower component has a thickness of 1-5 mm. 
     
     
       5. A method according to  claim 1  wherein the highest point on the convex upper surface is at least 0.5 inch higher than the lowest point on the convex surface. 
     
     
       6. A method according to  claim 1  wherein each of the covering members
 (1) has a circular outer periphery which is 60-300 inch long, and 
 (2) has a hole which passes through the covering member, the hole (i) having an inner circular periphery 5-40 inch long, and (ii) being positioned so that the distance between each point on the inner periphery and the closest point on the outer periphery is the same and is 15-24 inches. 
 
     
     
       7. A method according to  claim 1  wherein the closed cell polymeric foam has a density of 1.5-7 pounds per cubic foot. 
     
     
       8. A method according to  claim 1  wherein the closed cell polymeric foam is composed of a polyolefin containing a UV stabilizer. 
     
     
       9. A method of covering an exposed surface of water in a swimming pool, the method comprising maintaining a plurality of generally laminar covering members on the surface, each of the covering members comprising
 (1) an upper component having an upper surface, at least part of the upper surface being convex, the highest point on the convex upper surface being at least 0.5 inch higher than the lowest point on the convex surface, and the upper surface being (i) above the surface of the water and (ii) substantially impermeable to water, and 
 (2) a lower component which (i) is secured to the upper component, and (ii) comprises a lower portion which is immersed in the water and comprises an open cell polymeric foam having water absorbed therein. 
 
     
     
       10. A method according to  claim 9  wherein each of the covering members consists essentially of the upper component and the lower component. 
     
     
       11. A method according to  claim 10  wherein the upper component has a thickness of 7-60 mm and the lower component has a thickness of 0.5-40 mm. 
     
     
       12. A method according to  claim 11  wherein each of the covering members is a monolithic article wherein the upper component has a thickness of 20-40 mm, and the lower component has a thickness of 1-5 mm. 
     
     
       13. A method according to  claim 9  wherein each of the covering members
 (1) has a circular outer periphery which is 60-300 inch long, and 
 (2) has a hole which passes through the covering member, the hole (i) having an inner circular periphery 5-40 inch long, and (ii) being positioned so that the distance between each point on the inner periphery and the closest point on the outer periphery is the same and is 15-24 inches. 
 
     
     
       14. A method according to  claim 9  wherein the upper component is composed of a closed cell polymeric foam and the closed cell polymeric foam has a density of 1.5-7 pounds per cubic foot. 
     
     
       15. A method according to  claim 14  wherein the closed cell polymeric foam is composed of a polyolefin containing a UV stabilizer. 
     
     
       16. A method according to  claim 9  wherein each of the covering members
 (1) has a circular outer periphery which is 60-300 inch long, and 
 (2) has a hole which passes through the covering member, the hole (i) having an inner circular periphery 5-40 inch long, and (ii) being positioned so that the distance between each point on the inner periphery and the closest point on the outer periphery is the same and is 15-24 inches. 
 
     
     
       17. A method of covering an exposed surface of water in a swimming pool, the method comprising maintaining a plurality of separate, generally laminar covering members on the surface, each of the separate covering members (a) having an outer periphery which is circular or polygonal and (b) comprising
 (1) an upper component having an upper surface, at least part of the upper surface being convex, the highest point on the convex upper surface being at least 0.5 inch higher than the lowest point on the convex surface, and the upper surface being (i) above the surface of the water and (ii) substantially impermeable to water, and 
 (2) a lower component which (i) is secured to the upper component, and (ii) comprises a lower portion which is immersed in the water and comprises an open cell polymeric foam having water absorbed therein. 
 
     
     
       18. A method according to  claim 17  wherein each of the separate covering members is a monolithic article which consists essentially of the upper component and the lower component, the upper component has a thickness of 7-60 mm, and the lower component has a thickness of 0.5-40 mm.